For all kinds of existing energy sources in the earth, solar energy is the most widespread, the richest and the most uniformly distributed energy source. Solar energy can be used very easily. It is available every day, everywhere and for every body.
For all kinds of human energy consuming activities, cooking food and beverage is the most often activity and has the longest history. Every body in anywhere needs to cook the foods every day.
It is very interesting and valuable topic to use solar energy for food cooking. There are many efforts in this field. (Please refer to the existing patents).
The solar power on a unit earth area is not very large. The solar radiation intensity is varied from North to South and from morning to afternoon. It depends on the weather and is also different in four seasons, so that to develop an economic solar cooking appliance is always a challenge and need continue efforts.
In view of these difficulties, some solar cooking appliances tried to make the sunlight receiving area as large as possible. But the heat insulation for the received heat is difficult. Some solar cooking appliances follow and focus the sunlight using expensive automation system and need additional power to run the system. Some solar cooking appliances also use the heat storage materials. The materials may be expensive and not easy to get.
Therefore, it is an important topic for the industry to further develop and improve applications of the solar cooking technology to develop a set of economic and practicable solar cooking appliances.